Optimizations from server profile (#38290)

* Properly cache regexes in chat sanitization/accents

Wow I wonder if `new Regex()` has a cost to it *looks at server profile*.

* Avoid lag caused by Tippy command completions

CompletionHelper.PrototypeIDs explicitly says *not* to use it with EntityPrototype. Unsurprisingly, reporting a completion result for every entity prototype in the game is a *bad idea*.

* Add active count metrics to some high-load systems

Mover & NPCs

I suspect the thing that caused the Leviathan round to shit itself on performance is NPC spam in space or something. So let's verify that.

* Enable parallel processing on pow3r again

Originally disabled due to a theory of it causing bugs, it was re-enabled on Vulture, and I'm not aware of it having caused any issues there.

* Replace hashset with bitflags for AtmosMonitor alert types.

Allocating these hashsets was like 20% of the CPU of atmos, somehow.

* Cache HashSet used for space movement collider checks

Turns out this was a ton of server allocations. Huh.

Content.Server/Tips/TipsSystem.cs

@@ -68,9 +68,13 @@ public sealed class TipsSystem : EntitySystem
     {
         return args.Length switch
         {
-            1 => CompletionResult.FromHintOptions(CompletionHelper.SessionNames(), Loc.GetString("cmd-tippy-auto-1")),
+            1 => CompletionResult.FromHintOptions(
+                CompletionHelper.SessionNames(players: _playerManager),
+                Loc.GetString("cmd-tippy-auto-1")),
             2 => CompletionResult.FromHint(Loc.GetString("cmd-tippy-auto-2")),
-            3 => CompletionResult.FromHintOptions(CompletionHelper.PrototypeIDs<EntityPrototype>(), Loc.GetString("cmd-tippy-auto-3")),
+            3 => CompletionResult.FromHintOptions(
+                CompletionHelper.PrototypeIdsLimited<EntityPrototype>(args[2], _prototype),
+                Loc.GetString("cmd-tippy-auto-3")),
             4 => CompletionResult.FromHint(Loc.GetString("cmd-tippy-auto-4")),
             5 => CompletionResult.FromHint(Loc.GetString("cmd-tippy-auto-5")),
             6 => CompletionResult.FromHint(Loc.GetString("cmd-tippy-auto-6")),